Effect
Hastened and Lethargic
Hastened grants extra action and movement, but ordinary Haste leaves the target Lethargic when it ends.
While Hastened, the creature gains +2 Armour Class, Advantage on Dexterity saves, increased movement, and an extra action each turn.
The Haste spell requires Concentration. Losing it can trigger Lethargic, so protect the caster. Potions, spores, and other sources have their own durations and ending effects.